WATER OPERATION AND MAINTENANCE BULLETIN - Bureau of …€¦ · WATER OPERATION AND MAINTENANCE BULLETIN No. 183 March 1998 IN THIS ISSUE. . . • Reclamation Expands the Capabilities

W A T E R O P E R A T I O N

A N D M A I N T E N A N C E

B U L L E T I N

No. 183 March 1998

I N T H I S I S S U E . . .

• Reclamation Expands the Capabilities of its Computerized Flood Mapping Program

• Historic Waddell Dam Breached (in 1992)• Using Reclamation’s New Water Measurement Manual to

Save Water

UNITED STATES DEPARTMENT OF THE INTERIORBureau of Reclamation

For further information about the Water Operation andMaintenance Bulletin or to receive a copy of the annual index,contact:

Jerry Fischer, Managing Editor

Bureau of Reclamation

Operation and Structural Safety Group, Code D-8470

PO Box 25007, Denver CO 80225

Telephone: (303) 445-2748

FAX: (303) 445-6381

Email: [email protected]

This Water Operation and Maintenance Bulletin is published quarterly for the benefitof water supply system operators. Its principal purpose is to serve as a medium toexchange information for use by Reclamation personnel and water user groups inoperating and maintaining project facilities.

Although every attempt is made to ensure high quality and accurate information,Reclamation cannot warrant nor be responsible for the use or misuse of information that is furnished in this bulletin.

Cover photograph: New Waddell Dam and completed breachin historic Waddell Dam.

Any information contained in this bulletin regarding commercial products may not beused for advertisement or promotional purposes and is not to be construed as an

endorsement of any product or firm by the Bureau of Reclamation.

UNITED STATES DEPARTMENT OF THE INTERIOR Bureau of Reclamation

WATER OPERATION AND MAINTENANCE BULLETINNo. 183—March 1998

CONTENTS

Page

Reclamation Expands the Capabilities of its Computerized Flood Mapping Program . . . 1Historic Waddell Dam Breached (in 1992) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Using Reclamation’s New Water Measurement Manual to Save Water . . . . . . . . . . . . . . 15

1 For further information regarding this work, please contact Ronald E. Miller, Physical Scientist,Remote Sensing and Geographic Information Group, D-8260, by phone: (303) 445-2279 or email: [email protected]

RECLAMATION EXPANDS THE CAPABILITIES OF ITSCOMPUTERIZED FLOOD MAPPING PROGRAM

by Ron Miller1, Kurt Wille, Diane Williams, and Doug Clark

In the December 1996 issue of the Water Operation and Maintenance Bulletin, the Bureauof Reclamation (Reclamation) announced that it had adopted new standards for producingdam failure and flood release inundation maps. These standards were in response toCommissioner Beard’s directive to take reasonable and prudent actions to ensure the safetyof the public and to protect environmental resources potentially affected by incidents at ourfacilities. Inundation maps, descriptions of potentially flooded areas, tables showing traveltimes, and other pertinent information are necessary for local emergency management officialsto warn and evacuate possibly flooded areas.

Since that time, Reclamation’s Remote Sensing and Geographic Information Group (RSGIG)has expanded its suite of flood mapping capabilities. This work has been subdivided into two tasks. The first task is production of a standard map product that can be used forstandard operating procedures (SOP), emergency action plans, and risk assessments. Thesecond task is analysis of Topologically Integrated Geographical Encoding and Referencing(TIGER) System census data. Analysis of affected critical infrastructure as well as social andeconomic impacts is also either under development or under consideration. These mappingand analysis efforts will potentially make significantly more data available to emergencymanagers than they have had previously. Moreover, since these data can be distributed indigital form on CD-ROM, users can make use of them interactively. Users will be able to locate features on the landscape, set up queries, experiment with "what-if" scenarios, andperform modeling functions.

For the purposes of inundation mapping, hydraulic engineers estimate potential dam breachand operational flood boundaries using the DAMBRK model developed by the NationalWeather Service (NWS). In addition, the DAMBRK INTERFACE (DBI) software, whichwas developed by Reclamation’s Mid-Pacific Region Geographic Information System (GIS)Service Center, is also being tested and has actually been used in several DAMBRK studies. DBI is an Arc/Info based package designed to utilize GIS analytical capabilities to provideinput data for the NWS DAMBRK finite difference model. A toolkit of UNIX scripts, ArcMacro Language (AML) routines and graphical user interface menus has been designed towork within the GIS environment. The digital elevation model and related ancillary data areused to construct transects required by the model. The incorporation of GIS technologymakes "what-if" scenarios less cumbersome and reduces the subjectivity of deriving transectelevations and widths from topographic maps. Resulting output is in georeferenced digital

2 Water Operation and Maintenance Bulletin

form. These modeled inundation boundaries are delivered to RSGIG. If DBI software is not used, two additional steps are necessary. First, the hydraulic modeler must draft theinundation boundary onto quad sheets, and, second, the drafted output must be digitized in the RSGIG laboratory.

The flood inundation boundaries constitute the input data for the RSGIG "Dam Failure/Operational Release Automated Mapping Program" (AMP) developed in house. The AMP is a fully automated collection of applications written in AML to guide the flood mappingprocess from start to finish. Major steps include:

A) Development of vector data set1. Generate registration tic files2. Create 7.5 minute U.S. Geological Survey (USGS) quadrangle boundaries3. Digitize, edit, and attribute inundation boundaries4. Digitize, edit, and attribute cross-sections5. Map panel index coverage creation and attribution

B) Development of 7.5 minute digital raster graphics (DRGs)1. Scan quadrangle2. Initiate DRG registration and clipping3. Create a DRG mosaic4. Develop map panel index clipping

C) Map composition1. Solid fill inundation polygons and place on DRG background2. Link flood and flow data to visible cross-section lines3. Create an index map relating each map panel to the entire flood zone

D) Data archiving1. Compress and backup completed mapping project2. Archive and unarchive finished projects

It is also possible for the AMP to use existing SOP paper maps as input data. In theseinstances, the existing SOP inundation maps are color-scanned to produce digital images,registered to the related DRGs, and used as a template for onscreen digitizing.

The AMP application ensures that each flood mapping project is completed in an ordered,consistent, and efficient manner. Quality control procedures are in place at major junctures ofthe suite of programs. AMP map compositions become part of the SOP manuals distributedby Reclamation. Figure 1 is a black and white rendering of a standard SOP map produced byD-8260.

A second advance in inundation analysis is the calculation of resident populations living in theinundation zone. Reclamation recently gained access to TIGER files census block data fromthe U.S. Census Bureau that were reprocessed and put into Arc/Info format by theEnvironmental Protection Agency’s (EPA) Office of Information Resources Management. These files contain 1990 total resident population at the block level.

Water Operation and Maintenance Bulletin 3


A "block" is the smallest geographic unit for which the U.S. Census Bureau gathers demo-graphic data. These blocks are usually "small areas bounded on all sides by visible featuressuch as streets, roads, streams, and railroad tracks, and by invisible boundaries such as property lines, legal limits, and short imaginary extensions of streets and roads" (TechnicalDocumentation: TIGER/Line Census Files, 1992). The average population size of a censusblock is about 100 persons, but there can be considerable variation.

An extensive set of AML programs has been developed to capture, integrate, reproject, andanalyze these data to produce tables of the estimated numbers of persons living in theinundation zone by cross-sectional distance and leading edge arrival time. These basic dataalso become one of the inputs for population at risk and loss of life assessments. Figure 2 is a plot of census blocks in the inundation zone in proximity to Miles City on the YellowstoneRiver in Montana.

Emergency officials require information about a wide variety of data themes in order tomanage an emergency incident adequately. In recognition of this, Reclamation has begun to gather a variety of other attributed data themes. For instance, persons at risk are oftencrossing bridges, camping in recreation areas, or traveling on roads. Knowledge of which ofthese will be inundated is vital for purposes of evacuation. These themes have been gatheredfrom the U.S. Department of Transportation via the Federal Emergency Management Agency (FEMA) and from EPA. Knowledge of the location of other transport facilities is also vitalbecause they can both bring in supplies and assist in evacuation efforts. The location of airports has been provided by FEMA, and the rail network comes from EPA sources.

During an emergency crisis, the location of and information about certain critical facilities isalso vital. In view of this, Reclamation is gathering location and attribute information onhospitals, including name, address, number of beds, existence of a blood bank, total number ofregistered nurses, existence of burn care units, and so on. Reclamation is also gatheringinformation on schools, communication towers, and military installations. If funding becomesavailable, these basic data can be provided on CD-ROM to Reclamation area offices to assist them in their emergency management efforts. Figure 3 is a plot of criticalinfrastructure in the flood inundation zone near Miles City, Montana.

Other data vital to emergency management efforts will soon become available, if funding isapproved. Data themes such as electric powerplants; geological faults; gas pipes, plants, andstorage facilities; nuclear powerplants; water supply plants; oil refineries; seismic risk zones;superfund sites; sewer plants; tank farms; toxic release inventory sites; utility lines; non-Reclamation dams; custodial facilities such as nursing homes, orphanages, and correctionalfacilities; and religious institutions are currently available at nominal cost.

The data that Reclamation currently provides, along with other data which may soon becomeavailable, could become part of an Environmental Systems Research Institute ArcView"project." According to a recent survey, the vast majority of Reclamation regional and areaoffices now own some version of Arc/Info, ArcCad, or ArcView software. With thissoftware, emergency managers can interactively query the data for their own needs. In




addition, they will be able to supplement the basic package of data themes the Denver Office isproviding with others of local importance. Finally, it is entirely possible, using the Avenueprogramming capability associated with ArcView, to customize each project to suit the veryspecific decisionmaking needs of each office.

These data and Reclamation’s GIS capabilities may also be useful for facilitating otheremergency planning activities such as population at risk and loss of life assessment; trainingemergency management personnel; and performing orientation, table top, and functionalemergency exercises. Beyond this, GIS data can be integrated with other electronic decision-making and resource management tools such as an emergency information system for use in anactual disaster response situation.

Glossary of Terms

Computer, GIS, Mapping, and Modeling Terms

Cartography: The art and science of representing the features of the Earth’s surfacegraphically. Synonymous with map making.

Census Block: The smallest geographic area for which the U.S. Census Bureau gatherspopulation data. These blocks are generally rather small areas "bounded on all sides by visiblefeatures such as streets, roads, streams, and railroad tracks, and by invisible boundaries such asproperty lines, legal limits, and short imaginary extensions of streets and roads" (TechnicalDocumentation: TIGER/Line Census Files, 1992). This is the spatial unit of analysis for dambreach population at risk studies.

Compact Disc Read-Only Memory (CD-ROM): An optical data storage medium, readable bya computer having a CD-ROM disc drive.

DAMBRK: A flood model program that analyzes dam failure scenarios and uses hydro-dynamic theory to predict dam-break flood wave formation and routing; also known as theNational Weather Service Dam-Break Flood Forecasting Model. An enhanced user interfaceversion, developed by the BOSS Corporation, has been used for studies in the Denver Office.

Dam Break Interface (DBI): GIS front end for the DAMBRK model designed by the Mid-Pacific Region GIS Office to enable users to identify and visualize the cross-sections(including 3-D) and generate a set of input files for loading into DAMBRK. The DBI isdesigned to substantially reduce the time it takes to get cross-section data into DAMBRK,while enabling users to exercise more judgment on cross-section placement and other items. Users can visually inspect and edit the cross-sections before entering them into the model.


This GIS-based software (Arc/Info) can make DAMBRK run and then produces a digitalcoverage of the inundated area within a relatively short period of time. Improvements are stillbeing made to the program.

Data Set: A collection of similarly formatted records having like information (from one ormore data sources). Data sets contain columns and rows. The columns contain the datasubject. Examples might be census tract identifier, population, area, and fertility rate. Therows contain observations with measurements on each of the data subjects. Thus, census tract 22.05 might have 3975 inhabitants, an area of .025 square mile, and a fertility rate of 10 children per 1,000 women aged 15 to 45.

Digital Elevation Model (DEM): A raster (row and column) array of elevation values.

Digitizer: A device that converts analog information into a digital format. For flat graphicmaterial, such as maps, a digitizer can either be flatbed or scanning.

Digital Raster Graphics (DRG): Digital Raster Graphics file format. A 4-bit TIFF rasterimage of scanned and geocorrected 7.5 minute quads or other scale topographic maps, forexample, 1:100,000 and 1:250,000 scale maps.

Finite Difference Model: A particular kind of digital computer model based upon arectangular grid that sets the boundaries of the model and the nodes where the model will besolved.

Flood Inundation Boundary: Polygon delineated around the outer edge of a floodinundation area.

Format: The physical organization of data elements within a data set.

Geographic Information System (GIS): A complete sequence of computer and humanelements for acquiring, processing, storing, and managing spatial data.

Georeference: Raster image data or vector elements that have been registered to create adirect spatial relationship to actual ground features. A georeferenced soft copy or hard copyfeature must contain a map projection and scale.

Graphical User Interface (GUI): A software capability that uses pictures, buttons, menus,and icons to generate program input and output. Runs on a windows computer platform.

Hard Copy: Graphic and textual features that are plotted on paper, mylar, or other material.

Hardware: The physical components of a computer: central processing unit, memory, diskstorage, tape drives, etc.


Image: A two-dimensional data representation. Examples include a photograph or a multi-spectral imaging sensor’s data output.

Map: Usually a two-dimensional representation of all or part of the Earth’s surface, showingselected natural or manmade features or data, preferably constructed in a definite projectionwith a specified scale.

Mosaicing: An assemblage of images whose edges are clipped and matched to form acontinuous representation of a portion of the Earth’s surface.

Population at Risk: All individuals who, if they took no action to evacuate, would beexposed to flooding of any depth. The population at risk is dependent on the dam failure orflooding event analyzed.

Projection: A systematic construction of features on a plane surface to representcorresponding features on a spherical surface. Common types are conic, cylindrical, andazimuthal. Each has strengths and weaknesses in terms of showing true distance, true area,and true shape.

Raster: A cellular data structure or organization of spatial data. In a raster structure, a valuefor the parameter of interest (elevation in feet above some known point, land use class from aspecified list, etc.) is developed for every cell in an array over space.

Registration: Superposition of locations on an image or map with coordinate valuesassociated with one of a variety of projections which model locations on the Earth’s surface.

Scale: The ratio of map distance to Earth distance. Thus, in a 1:24000 scale map, onecentimeter, inch, or foot equals 24,000 centimeters, inches, or feet on the ground. Graphicscales typically show equivalent map and ground distance in the form of a line or bar.

Topologically Integrated Geographic Encoding and Referencing System (TIGER): Ageometric and tabular representation for demographic data that can be used for floodinundation impact analysis.

Topography: The collective features of the surface of the Earth, especially the relief andcontour of the land.

Travel Time: Time measured from the dam breach location to flooding at a particularlocation. The flood level corresponding to that travel time is usually either the arrival of theleading flood wave or the peak flow at that location.

UNIX: A computer operating system which is interactive, time-sharing, multiple user, andmultiple tasking.


Vector: Generally, a quantity possessing both numerical value and direction. In terms of GIS,typically representing a boundary between spatial objects. Vector GISs typically displayspatial data in terms of points, lines, and polygons, as opposed to raster data, which displaythem as picture elements.

Emergency Response Terms

Emergency Information System (EIS): An emergency management computer application. EIS integrates maps, data bases, models and sensors, and communications all into onepackage. The mapping capabilities range from USGS maps on CD-ROM to photographs orsatellite images calibrated to their proper latitude and longitude. EIS supports TIGER linefiles from the U.S.Census Bureau and nearly 20 GIS formats converted through the utility inArcView and scanned maps or images (PCX, TIFF, BMP, and CUT). The data bases includehazard site analysis, census data, emergency plans, special needs, incident logs, incidentactions, and incident situation reports.

The communications package is titled ECOMM. This module allows for the exchange ofmaps and data with any EIS user and commercial programs using the Xmodem, CRC, andKermit protocols, National Weather Service Wire, cellular and landline telephone systems,packet radio systems, flood warning systems, and meteorological towers and sensors.


HISTORIC WADDELL DAM BREACHED (IN 1992)

On the cold, rainy morning of December 4, 1992, Waddell Dam was breached, and a largepart of this historic structure sunk below the waves of Lake Pleasant. Although the weatherproved to be a deterrent (probably a frigid 50 degrees) for many less hardy souls, representa-tives from the Phoenix Area Office, Maricopa Water District, Central Arizona WaterConservation District, Arizona Game and Fish Department, Maricopa County Parks andRecreation Department, and even the Coast Guard, braved the elements to witness thebreaching of the original dam. Members of the local news media documented this historicalevent. Why would anyone, especially the Bureau of Reclamation (Reclamation), want tobreach a dam as beautiful as Waddell Dam?

Reclamation completed construction of New Waddell Dam, located about 1/2 mile down-stream of Waddell Dam, in October 1992. The historic Waddell Dam, constructed in 1927 by private interests, was the largest multiple arch dam in the world. New Waddell Dam wasconstructed to store Colorado River water delivered by the Hayden-Rhodes Aqueduct(formerly the Granite Reef Aqueduct) under the Central Arizona Project. With New WaddellDam, the Central Arizona Water Conservation District could perform scheduled maintenanceon the canal between Lake Havasu on the Colorado River to the turnout for the reversibleWaddell Canal to the new dam while deliveries continued to downstream customers of thedistrict. The dam could also provide flood protection by controlling riverflows into thePhoenix metropolitan area from the Agua Fria. The new reservoir added 6,300 surface acresto Lake Pleasant, tripling the size of the lake and greatly increasing the recreational value ofLake Pleasant Regional Park. Maricopa Water District, the owner of the original WaddellDam, was provided an outlet to allow diversions into their canal distribution system.

Because the new reservoir’s water level may fluctuate as much as 125 feet during a year’soperation, the recreation facilities would need to be accessible during both high and low waterperiods. A new marina was located between the original dam and the new downstream dam. With the top of the original dam being exposed during low water levels, plans were to cut abreach in Waddell Dam to allow boaters to safely travel to the marina and provide storagecontinuity to the new dam.

First, the old roadway deck, spillway gates, piers, and miscellaneous machinery were removed. Then, a subcontractor, Advanced American Diving Service, Inc., of Oregon was hired tocreate a breach 224 feet wide and 70 feet deep in the original dam. The breach consisted ofcutting through the concrete structure with a diamond-wire saw. Four arch barrels and threebuttresses were cut using these methods. A few bolts were installed to hold the large blocksof concrete in place until all the cutting was complete. The bolts were then blasted withdemolition charges which allowed the separated sections to fall safely into the lake.

The following photos are courtesy of the Department of the Interior, Bureau of Reclamation,Phoenix Area Office and Arizona Projects Office.


Historic Waddell Dam, constructed in 1927.

New Waddell Dam, completed in 1992, and historic Waddell Dam before the breach.


Blocks of concrete from historic Waddell Dam sink into Lake Pleasant.

Blocks of concrete at historic Waddell Dam begin to fall away after cuts to create breach.


A breach is created in historic Waddell Dam.


1 Technical Specialist, U.S. Bureau of Reclamation, Denver, Colorado.

Figure 1.—Weir box turnout with Cipolletti Weir.

USING RECLAMATION’S NEW WATER MEASUREMENT MANUALTO SAVE WATER

By Clifford A. Pugh1

What is the Water Measurement Manual?

The Water Measurement Manual, Third Edition, is a reference updating water measurementinformation previously published by the Bureau of Reclamation. Previous editions date backto 1913. The 1997 edition contains information about several new technologies, includingacoustic and electromagnetic flow meters, as well as contributions from the AgriculturalResearch Service and the Natural Resources Conservation Service.

The new manual places increased emphasis on the use of long-throated flume measurementstructures. Ramp flumes are a form of long-throated flume. These structures can be appliedin situations where Parshall flumes might have been used in the past, but they are easier to


fabricate and more tolerant of high tailwater conditions. Therefore, they are ideal forinstallation in existing canal systems, where available head (elevation) may be limited. Long-throated flumes are also preferable because they can be installed within the existing canalsection. Information on Parshall flumes has been reduced in the new manual and incorporatedinto the more general "Flumes" chapter.

New chapters added to the manual are

• Basic Concepts Related to Flowing Water and Measurement• Selection of Water Measuring Devices • Measurement Accuracy • Inspection of Water Measurement Systems • Acoustic Flow Measurement • Discharge Measurement Using Tracers

Other chapters with applicable information for farm installations are

• Weirs• Flumes• Submerged Orifices• Special Measurements in Open Channels• Measurements in Pressure Conduits

Why do we Need to Measure Water?

The ultimate goal of water measurement is to conserve water through improved managementof its distribution and application. Accurate water measurement helps in the distributionbecause it is very difficult to manage something when you do not know precisely how muchyou are using.

Management of water supplies is changing. Increasing competition exists between power,irrigation, cities, industry, recreation, aesthetic, and fish and wildlife uses. Within the UnitedStates, critical examinations of water use will be based on consumption, perceived waste,population density, and impact on ecological systems and endangered species. Water districtsand farmers will need to document their use of water and seek ways to extend the use of theirshare of water by the best available technologies. Best management measures and practiceswithout exception include conservation of water.

Rather than finding and developing new sources, water often can be supplied moreeconomically by conservation. Each cubic foot of water recovered as a result of improvedwater management costs less than supplying the same amount from a new source. Bettermeasurement procedures extend the use of water because lack of information usually results


in the delivery of excess water or loss through waste. Attention to measurement, manage-ment, and maintenance will take advantage of the farmer's water and help prevent reducedyields and other crop damage caused by underwatering or overwatering.

How to use the Water Measurement Manual to Conserve Water

The "Flumes," "Weirs," and "Measurements in Pressure Conduits" chapters will provide muchof the information and illustrations needed to install flow measurement devices on farms andcanals. Tables in the text and the appendix also list flows for some of the more commonmeasuring devices, making the manual a valuable asset in the field.

Special attention should be given to the "Long Throated Flumes," section 8-8, since theseflumes are the most adaptable to existing canals and require less complicated constructionforming (figure 2). Usually, the farmer can construct the device in place. The flumes have fewproblems with debris, sediment, and downstream submergence. Measurement of the flow issimple since only the upstream water depth is needed. The new manual provides standarddesigns for typical situations, and straightforward computer software is also available fordeveloping customized flume designs.

The Water Measurement Manual can be accessed on the World Wide Web athttp://ogee.do.usbr.gov/fmt/wmm/ or a hard bound version can be purchased from theGovernment Printing Office, Superintendent of Documents (202) 512-1800, fax (202) 512-2250, PO Box 371954, Pittsburgh PA 15250-7954. The stock number is S/N 024-003-00180-5. The price for U.S. customers is $34.00. For customers outside ofthe U.S., the price is US$42.50. Reclamation offices can order copies from the warehouse in Denver, mailing code D-7913, attention: T Marvel.


Mission

The mission of the Bureau of Reclamation is to manage, develop, andprotect water and related resources in an environmentally andeconomically sound manner in the interest of the American public.

The purpose of this bulletin is to serve as a medium of exchanging operation andmaintenance information. Its success depends upon your help in obtaining andsubmitting new and useful operation and maintenance ideas.

Advertise your district’s or project’s resourcefulness by having an article published inthe bulletin—let us hear from you soon!

Prospective articles should be submitted to one of the Bureau of Reclamation contactslisted below:

Jerry Fischer, Technical Service Center, ATTN: D-8470, PO Box 25007, Denver,Colorado 80225-0007; (303) 445-2748, FAX (303) 445-6381; email: [email protected]

Vicki Hoffman, Pacific Northwest Region, ATTN: PN-3234, 1150 North Curtis Road,Boise, Idaho 83706-1234; (208) 378-5335, FAX (208) 378-5305

Dena Uding, Mid-Pacific Region, ATTN: MP-430, 2800 Cottage Way, Sacramento,California 95825-1898; (916) 978-5229, FAX (916) 978-5290

Bob Sabouri, Lower Colorado Region, ATTN: BCOO-4844, PO Box 61470, BoulderCity, Nevada 89006-1470; (702) 293-8116, FAX (702) 293-8042

Don Wintch, Upper Colorado Region, ATTN: UC-258, PO Box 11568, Salt LakeCity, Utah 84147-0568; (801) 524-3307, FAX (801) 524-5499

Tim Flanagan, Great Plains Region, ATTN: GP-2400, PO Box 36900, Billings,Montana 59107-6900; (406) 247-7780, FAX (406) 247-7793